depends on the type of ducks im hunting. some cases i put out 90 to a 100 single line in 12 ft of water when were hunting with bluebills,blacks,redheads,cans and mallards when hunting a certian area around me and then in another spot we put out 6 to 7 dozen mallards and a dozen blue bill. with full body mallards on land and 2 mojos. it also depends on how the ducks are in your area in like in mine the mallards and blacks raft up with the diver out on the big water. and another thing is the amount of ducks in your area you shouldn't have huge spreads when there aren't that many ducks in the area. come flight bird time put them all out

We hunt a big river and normally hunt over 3 to 4 dozen decoys but somedays we've killed our limit on only a dozen decoys. I guess if your a good caller and can get their attention with small spreads you will be fine